BACKGROUND: In 2007, a US Air Force training facility reported a cluster of severe respiratory illnesses associated with a rare human adenovirus (Ad) serotype, Ad14. We investigated this outbreak to better understand its epidemiology, clinical spectrum, and associated risk factors. METHODS: Data were collected from ongoing febrile respiratory illness (FRI) surveillance and from a retrospective cohort investigation. Because an Ad7 vaccine is in development, Ad7 antibody titers in pretraining serum samples from trainees with mild and those with severe Ad14 illness were compared. RESULTS: During 2007, an estimated 551 (48%) of 1147 trainees with FRI were infected with Ad14; 23 were hospitalized with pneumonia, 4 required admission to an intensive care unit, and 1 died. Among cohort members (n = 173), the Ad14 infection rate was high (50%). Of those infected, 40% experienced FRI. No cohort members were hospitalized. Male sex (risk ratio [RR], 4.7 [95% confidence interval {CI}, 2.2-10.1]) and an ill close contact (RR, 1.6 [95% CI, 1.2-2.2]) were associated with infection. Preexisting Ad7 neutralizing antibodies were found in 7 (37%) of 19 Ad14-positive trainees with mild illness but in 0 of 16 trainees with Ad14 pneumonia (P = .007). CONCLUSIONS: Emergence of Ad14, a rare Ad serotype, caused a protracted outbreak of respiratory illness among military recruits. Most infected recruits experienced FRI or milder illnesses. Some required hospitalization, and 1 died. Natural Ad7 infection may protect against severe Ad14 illness.
BACKGROUND: In 2007, a US Air Force training facility reported a cluster of severe respiratory illnesses associated with a rare human adenovirus (Ad) serotype, Ad14. We investigated this outbreak to better understand its epidemiology, clinical spectrum, and associated risk factors. METHODS: Data were collected from ongoing febrile respiratory illness (FRI) surveillance and from a retrospective cohort investigation. Because an Ad7 vaccine is in development, Ad7 antibody titers in pretraining serum samples from trainees with mild and those with severe Ad14 illness were compared. RESULTS: During 2007, an estimated 551 (48%) of 1147 trainees with FRI were infected with Ad14; 23 were hospitalized with pneumonia, 4 required admission to an intensive care unit, and 1 died. Among cohort members (n = 173), the Ad14 infection rate was high (50%). Of those infected, 40% experienced FRI. No cohort members were hospitalized. Male sex (risk ratio [RR], 4.7 [95% confidence interval {CI}, 2.2-10.1]) and an ill close contact (RR, 1.6 [95% CI, 1.2-2.2]) were associated with infection. Preexisting Ad7 neutralizing antibodies were found in 7 (37%) of 19 Ad14-positive trainees with mild illness but in 0 of 16 trainees with Ad14 pneumonia (P = .007). CONCLUSIONS: Emergence of Ad14, a rare Ad serotype, caused a protracted outbreak of respiratory illness among military recruits. Most infected recruits experienced FRI or milder illnesses. Some required hospitalization, and 1 died. Natural Ad7 infection may protect against severe Ad14 illness.
Authors: Huo-Shu H Houng; Lisa Lott; Heping Gong; Robert A Kuschner; Julia A Lynch; David Metzgar Journal: J Clin Microbiol Date: 2009-04-29 Impact factor: 5.948